Improved exhaust-fan



UNITED STATES PATENT OFFICE.

RANSOM COOK, OF SARATOGA SPRINGS, NINV YORK.

IM PRovi-:D Ex HAU sT-FAN.

Specification forming part of Letters Patent No. 33,693, dated November 12, 1861.

To all whom it may concern.-

Beit known that I, RANSOM COOK, of Saratoga Springs, in the county of Saratoga and State of New York, have invented a new and improved exhaustfan for the purpose of withdrawing impure air from polishing and grinding rooms, tunnels, and mines; and I do hereby declare that the following is a full and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, and to the letters of reference marked thereon, in which- Figure lis an elevation of my apparatus as used for Ventilating grinding-rooms. A is a cylinder with which a trunk or tube, through which the foul air is to be drawn, should be connected. B is the fan-wheel 5 c c c, the vanes or fans.

Fig. 2 shows the outer end of the cylinder which projects through the wall of the building where it is used. O is the annular opening through which the air is drawn by the fanwheel.

Fig. 3, No. 3, shows the inside of the fanwheel and the form of the vanes or fans c c c, the iat ring D shown on No. 4 not being yet attached. No. 4, Fig. 3, shows the inside of the fan-wheel when finished. The angular line E on Fig. 3 shows the shape in which the vanes or fans are bent, Athe arrow showing that part of the vane which is inserted within the wheel and which throws the air from it when in motion.

In constructing this apparatus the cylinder A, Fig. 1, may be made of either wood or metal, care being taken to secure a suitable box in the center of it, in which the shaft of the fan-wheel is to turn. The disk or plate of the wheel is found to answer well when properly made of wood, if used only in situations where it is kept dry; but it is better when made of thin metal and corrugated so as to secure accuracy and firmness without much weight. In most cases the diameter of the wheel and cylinder should be from two to three feet. The vanes or fans, being bent as shown at E, Fig. 3, instead of having the end within the wheel set in a line radiating from its center, may be inclined some fifteen or twenty degrees from a radial line, with the inner end point-ing in the same direction as that in which the wheel turns. The parts of the vanes which continue along the periphery of the wheel should be made to approach each other until the throats through which the air is thrown from the wheel are not more than halt' the size of the interior spaces between the vanes, where the rare or uncompressed air is received. This arrangement enables the fan to exhaust air much more effectually than it will when the spaces between the vanes on the periphery are left entirely open, while less power is required for driving it.

The iiat ring D, Fig. 3, No. 4, should be secured to each vane for the purpose of keeping both the vanes and ring firmly in proper position. The ring should revolve as near as possible to the end of the cylinder without actual contact. The width of the vanes, and consequently width of the space between the disk of the wheel and flat ring D, should be governed by the quantity of air which the proprietor wishes to remove per minute. The velocity with which the fan is to rotate is an important item in making an estimate 0f the proximity toward a vacuum, which may be obtained by this instrument. The vanes need not extend inwardly toward the center of the wheel more than from one-seventh to onesixth of its diameter 5 but this should be varied according to the distance between them.

t will be seen that when in use no air can reach the interior of the wheel, except by 'passing through the cylinder, for even in the small space between the ring D and end of the cylinder the air is thrown outward by the centrifugal force of the revolving ring. The vanes, being short, take up the air so near the periphery or the wheel that they instantly throw it off without consuming power by whirling it around within the wheel, and consequently remove the air with greater expedition than long ones.

In using this fan for Ventilating dry grinding or polishing rooms I insert the cylinder A in the wall of the building, allowing it and the fan-wheel to project outwardly beyond the face of the wall, the pulley on the shaft of the wheel being kept within the room, where the belt for turning it would be kept dry. I place a trunk or tube close to and parallel with a row of wheels and connect said trunk with the cylinder A in any manner that will secure a free passage of air from the trunk to the cylinder and allow the belt Vfor driving the fan to pass over the pulley. Opposite each lgrinding-Wheel I cut an opening in the trunk, through which the dust or cuttings of the Wheels are discharged into it by the joint instrumentality of the centrifugal force of the grinding-Wheels, and the partial vacuum maintained in the trunk by the fan-Wheel, which draws the dust through the annular opening" in the cylinder (marked O, Fig. 2) and throws it ott into the free atmosphere.

In drawingr overheated air or offensive gases from a room no trunk is necessary, for the air will be more rapidly removed by taking off the cylinder-head next to the pulley.

In Ventilating` mines and tunnels, or in any situation Where the belt would be protected from injury, the shaft ot the fan-wheel may be placed outside of the cylinder, instead of passing,` through it, keeping' the wheel in the saine position, as shown. A tube 'for Withbe connected with cylinder A andy extend t0 the reinotest part ot the excavation to be ventilated, so that as foul air is Withdrawn it may be replaced by pure air from Without by its natural pressure. It may be found desirable in deep excavations, Where cool air is the principal object sought, to place the exhaust-fan at the bottom of the mine and suck the air from above, it being found to require much less power to suck or draw a given quantity of air th rough a lengthy tube than is necessary to force the'same through it.

That I claim as my invention, and desire to secure by Letters Patent, is-

The construction ot an exhaust-fan in the manner substantially as hereinbefore described.

RANSOM COOK.

Vitnesses:

SIMON MILLIGAN, M. T. OooK. 

